Truing apparatus for grinding wheels



May 4, 1937; H. o. KRANICH 2,079,076

TRUING APPARATUS FOR GRINDING WHEELS Filed April 5, 1931 2 Sheets-Sheet 1 IE 1 l INVENTOR Henry 0. Kranlch ATTORNEY May 4,1937. H. o. KRANICH TRUING APPARATUS FOR GRINDING WHEELS Filed April 3, 1931 2 Sheets-Sheet 2 1 l v i) INVENTOR Henry O.l(ranl,ch

ATTORNEY Patented May 4, 1937 UNIT-ED STATE-S PATENT OFFICE TRUING APPARATUS FOR GBlND ING WHEELS Henry 0. Kranich, Toledo, Ohio, assignor to Libbey-Owens-Ford Glass Company, Toledo, Ohio, a corporation of Ohio Application April 3, 1931, Serial No. 527,441

3 Claims. (01. 511-241) a grinding machine having a grinding or rough- I ing plate or wheel rotatable about a substantially vertical axis. The edges of the glass sheets are'ground upon a machine of this character by 10 bringing the said edges into engagement with the upper surface of the grinding wheelduring rotation thereof in a manner well known in the art. In this type of -machine, the upper working surface of the roughing wheel or plate will,

after a certain period of use, become dished or formed with a slight recess or depression therein and, when this occurs, itis desirable to true or dress the roughing wheel whereby to remove the dished-out portion or recess and restore a plane grinding surface thereto.

An important object of the invention, therefore, is the provision of means associated with a grinding machine of the above character for truing or dressing the roughing wheel or plate after it has become worn.

. Another object of the invention is the provision of means of the above character adapted to function in a manner to grind'away the roughing wheel so as to remove any recess or depression 30. therein and restore a plane working surface thereto.

A further object of the invention is the provision of a freely rotatable truing or dressing block mounted above the roughing wheel and normally maintained but of engagement there- ,with, but which can be lowered upon the said wheel when it is desired to true or dress the- Fig. 3 is a fragmentary section of the rough- Y ing wheel after truing. p The grinding machine herein provided embodies generally a supporting standard or base portion 5 carrying at its upper end a basin or tub 6. Mounted centrally within the base portion is a vertically disposed shaft 1 positively driven in any well known manner such as by means of a worm 8 carried by a drive shaft 9 and meshing with worm. gear ill fixed to the lower end of vertical shaftl. The said shaft l projects upwardly through a bearing support H, and mounted uponthe upper end thereof is a grinding or roughing wheel or plate l2 carried upon bearing support it and being held in position by means of a nut l3. The basin 6 surrounds the roughing wheel .and is slightly larger in diameter than the same so that it may catch all of the surplus abrasive or other grinding medium which may be employed in the grinding operation.

In the use of a grinding machine of the above character, the roughing wheeli2 is preferably continuously rotated. When it is desired to H grind the edges of a glass sheet or plate it, the said sheet is manually held in a vertical position above the roughing wheel as indicated by the broken lines in Fig. I, with the edge to be ground in engagement therewith. This edge is then ground by the rotation of the grinding wheel in conjunction with a suitable abrasive material which is usually supplied thereto. After the roughing wheel has'been in use for a certain length of time, the .upper surface thereof becomes dished-out or recessed as indicated at E5 in Fig. 2, and when this occurs it is desirable that this recess or depression be removed so that a plane grinding surface will be restored to the roughing wheel.

As pointed out above, the present invention contemplates the provision of means for truing or dressing the roughing wheel after it becomes worn. The means herein provided for this purpose consists of a truing or dressing member orblock i8 preferably of cast iron and mounted above the roughing wheel I2. The truing block is carried at the lower end of a vertical spindle H which projects upwardly through a bracket arm l8 carried by the upwardly extending portion IQ of the basin 6. The truing block i6 is normally mounted in an elevated position above the roughing wheel as shown by the broken lines in Fig. 1, and may bd'maintained in such posi- Htion by means of one or more set screws or the relative thereto. Thus, the truing block is provided with a centrally disposed recess 2! within which the lower end of spindle I1 is received, and encircling the spindle within the recess is a ball bearing assembly 22 which will allow the.

5 desired rotation of block l6 with respect to spindle l1 and also a limited amount of universal rocking movement. When the block i6 is raised to its inoperative position, it is held upon the spindle I! by a nut 23. The ball bearing as- 10 sembly 22 is protected from grit and other foreign matter by means of the plate 24 through which the spindle ll projects and also by a shield 25 carried by the said spindle and encircling said plate.

During the normal operation of the grinding machine, the truing block I6 is maintained in an elevated position in spaced relation to and out of contact with the roughing wheel I2. However, after the roughing wheel has become worn and it is desired to true or dress the same, the block I6 is lowered so that it rests freely upon the roughing Wheel. The roughing wheel is then positively driven and the rotation thereof will efiect the desired rotation of the truing block I6.

The truing block acting upon the roughing wheel will function to grind .out the recess or depression l5 therein so that a plane upper grinding surface will be restored thereto as indicated at 26 in Fig. 3. From the above, it will be readily 30 seen that there has been provided novel and simplified means for dressing the roughing wheel in a rapid, convenient and eflicient manner and without the necessity of removing the roughing wheel from the machines. Consequently, considerable time and labor can be saved in the dressing operation.

It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same,

' 40 and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. In a machine for use in grinding the edges of glass sheets or plates, the combination with a grinding wheel rotatable about a substantially vertical axis in a fixed horizontal plane, of a freely rotatable dressing tool adapted to rest freely upon the grinding wheel for truing the upper surface thereof, a vertically disposed spindle, and means for loosely connecting the dressing tool to the lower end of said spindle so that it may freely rotate relative thereto and also have a limited amount of universal rocking movement.

2. In a machine for use in grinding the edges of glass sheets or plates, the combination with a grinding wheel rotatable about a substantially vertical axis in a fixed horizontal plane, of a freely rotatable annular dressing tool adapted to rest freely upon the grinding wheel for truing the upper surface thereof, said dressing tool being driven by the rotation of said grinding wheel, a basin surrounding the grinding wheel and having a portion thereof projecting above said wheel, a horizontally disposed bracket arm carried by the projecting portion of the basin, a vertical spindle passing through the bracket arm, and means for connecting the dressing tool to the lower end of the spindle so that it may freely rotate relative thereto and also have a limited. amount of universal movement.

3. In a machine for use in grinding the edges of glass sheets or plates, the combination with a rotatable grinding wheel, of a rotatable dressing tool adapted to engage the working face of the grinding wheel for truing the same, a spindle, and means for connecting the dressing tool to said spindle so that it may have a limited amount of universal rocking movement.

HENRY 0. KRANICH. 

